1. Field of the Invention
The invention relates to the field of spread spectrum communications and, more particularly, to error detection and correction of digital data in such communications.
2. Prior Art
U.S. Pat. No. 4,918,690 describes the use of plurality of cells in a network which senses, communicates and controls. In a typical application a change in a light switch state is sensed by one cell, this change in state is communicated to a second cell over power lines, and a light is controlled by the second cell in response to the change in state of the switch. The cells typically interface with a network (e.g., power lines) through transceivers. U.S. Pat. No. 4,979,183 describes a transceiver which uses a spread spectrum signal for use in such a network. Other patents describing spread spectrum communications particularly for power line communications are U.S. Pat. Nos. 4,864,589; 4,641,322; 4,918,707 and 5,090,024. Other spread spectrum communication links are described in U.S. Pat. Nos. 4,866,733; 4,905,221; 4,748,636 and 4,879,713.
The present invention is directed towards the detection and correction of errors in connection with data communicated by a spread spectrum signal. Error correcting codes are well-known in the art, such as a Hamming code. As will be seen, the present invention permits the detection and correction of errors with substantially less overhead than do standard error correcting codes. The present invention makes use of a "hint" derived from the condition of the signal as discussed in the Detailed Description of the Invention.